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Systolic time intervals in chronic severe anaemia and effect of diuretic and digitalis
Insights
Systolic time intervals in severe anemia patients are similar to healthy individuals. Frusemide affects these intervals by reducing preload, impacting cardiac function.
Area of Science:
- Cardiology
- Physiology
- Hematology
Background:
- Chronic severe anemia can affect cardiovascular function.
- Systolic time intervals (STI) are non-invasive indicators of left ventricular function.
- Previous research on STI in anemia has yielded varied results.
Purpose of the Study:
- To compare STI in patients with chronic severe anemia and healthy controls.
- To investigate the effects of frusemide and digoxin on STI in anemic patients.
Main Methods:
- Simultaneous high-speed recordings of electrocardiogram, phonocardiogram, and carotid pulse.
- Measurement of heart rate, electromechanical systole (QS2), pre-ejection period index (PEPI), left ventricular ejection time index (LVETI), and PEP/LVET ratio.
- Intravenous administration of frusemide and digoxin in a subset of anemic patients.
Main Results:
- No significant differences in baseline STI parameters between anemic and control groups.
- Frusemide administration prolonged PEPI, increased PEP/LVET, increased heart rate, and shortened LVETI in anemic patients.
- Digoxin did not significantly alter QS2 or heart rate in anemic subjects.
Conclusions:
- Left ventricular function in chronic severe anemia, assessed by STI, is comparable to normal controls.
- Frusemide's effects on STI are attributed to preload reduction, shifting cardiac function along the Frank-Starling curve.
- Digoxin does not significantly impact STI in this anemic cohort.
Abstract:
Systolic time intervals were measured from simultaneous high speed recordings of the electrocardiogram, phonocardiogram, and carotid artery pulse in 15 men with chronic severe anaemia not in heart failure and with a normal heart size, and in 15 normal men. Heart rates, electromechanical systole (QS2), pre-ejection period index (PEPI), left ventricular ejection time index (LVETI), and the ratio of pre-ejection period to left ventricular ejection time (PEP/LVET) did not differ significantly in the two groups. After the intravenous administration of frusemide in 10 of the anaemic patients, the pre-ejection period index was prolonged, the PEP/LVET ratio increased, heart rate increased, and the left ventricular ejection time index shortened. Intravenous digoxin did not alter the QS2 interval and heart rate significantly in the anaemic subjects. Left ventricular function in chronic severe anaemia as measured by systolic time intervals does not differ from that of normal controls. The effect of frusemide on the systolic time intervals is explained as an effect of the fall in preload, bringing cardiac function further down on the ascending limb of the Frank-Starling curve. Other related studies are discussed.